git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/events/evgpe.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evgpe - General Purpose Event handling and dispatch
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2007, R. Byron Moore
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include <acpi/acevents.h>
  46 #include <acpi/acnamesp.h>
  47
  48 #define _COMPONENT          ACPI_EVENTS
  49 ACPI_MODULE_NAME("evgpe")
  50
  51 /* Local prototypes */
  52 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ev_set_gpe_type
  57  *
  58  * PARAMETERS:  gpe_event_info          - GPE to set
  59  *              Type                    - New type
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Sets the new type for the GPE (wake, run, or wake/run)
  64  *
  65  ******************************************************************************/
  66
  67 acpi_status
  68 acpi_ev_set_gpe_type(struct acpi_gpe_event_info *gpe_event_info, u8 type)
  69 {
  70         acpi_status status;
  71
  72         ACPI_FUNCTION_TRACE(ev_set_gpe_type);
  73
  74         /* Validate type and update register enable masks */
  75
  76         switch (type) {
  77         case ACPI_GPE_TYPE_WAKE:
  78         case ACPI_GPE_TYPE_RUNTIME:
  79         case ACPI_GPE_TYPE_WAKE_RUN:
  80                 break;
  81
  82         default:
  83                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  84         }
  85
  86         /* Disable the GPE if currently enabled */
  87
  88         status = acpi_ev_disable_gpe(gpe_event_info);
  89
  90         /* Type was validated above */
  91
  92         gpe_event_info->flags &= ~ACPI_GPE_TYPE_MASK;   /* Clear type bits */
  93         gpe_event_info->flags |= type;  /* Insert type */
  94         return_ACPI_STATUS(status);
  95 }
  96
  97 /*******************************************************************************
  98  *
  99  * FUNCTION:    acpi_ev_update_gpe_enable_masks
 100  *
 101  * PARAMETERS:  gpe_event_info          - GPE to update
 102  *              Type                    - What to do: ACPI_GPE_DISABLE or
 103  *                                        ACPI_GPE_ENABLE
 104  *
 105  * RETURN:      Status
 106  *
 107  * DESCRIPTION: Updates GPE register enable masks based on the GPE type
 108  *
 109  ******************************************************************************/
 110
 111 acpi_status
 112 acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info,
 113                                 u8 type)
 114 {
 115         struct acpi_gpe_register_info *gpe_register_info;
 116         u8 register_bit;
 117
 118         ACPI_FUNCTION_TRACE(ev_update_gpe_enable_masks);
 119
 120         gpe_register_info = gpe_event_info->register_info;
 121         if (!gpe_register_info) {
 122                 return_ACPI_STATUS(AE_NOT_EXIST);
 123         }
 124         register_bit = (u8)
 125             (1 <<
 126              (gpe_event_info->gpe_number - gpe_register_info->base_gpe_number));
 127
 128         /* 1) Disable case.  Simply clear all enable bits */
 129
 130         if (type == ACPI_GPE_DISABLE) {
 131                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
 132                                register_bit);
 133                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 134                 return_ACPI_STATUS(AE_OK);
 135         }
 136
 137         /* 2) Enable case.  Set/Clear the appropriate enable bits */
 138
 139         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 140         case ACPI_GPE_TYPE_WAKE:
 141                 ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
 142                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 143                 break;
 144
 145         case ACPI_GPE_TYPE_RUNTIME:
 146                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
 147                                register_bit);
 148                 ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
 149                 break;
 150
 151         case ACPI_GPE_TYPE_WAKE_RUN:
 152                 ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
 153                 ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
 154                 break;
 155
 156         default:
 157                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 158         }
 159
 160         return_ACPI_STATUS(AE_OK);
 161 }
 162
 163 /*******************************************************************************
 164  *
 165  * FUNCTION:    acpi_ev_enable_gpe
 166  *
 167  * PARAMETERS:  gpe_event_info          - GPE to enable
 168  *              write_to_hardware       - Enable now, or just mark data structs
 169  *                                        (WAKE GPEs should be deferred)
 170  *
 171  * RETURN:      Status
 172  *
 173  * DESCRIPTION: Enable a GPE based on the GPE type
 174  *
 175  ******************************************************************************/
 176
 177 acpi_status
 178 acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info,
 179                    u8 write_to_hardware)
 180 {
 181         acpi_status status;
 182
 183         ACPI_FUNCTION_TRACE(ev_enable_gpe);
 184
 185         /* Make sure HW enable masks are updated */
 186
 187         status =
 188             acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_ENABLE);
 189         if (ACPI_FAILURE(status)) {
 190                 return_ACPI_STATUS(status);
 191         }
 192
 193         /* Mark wake-enabled or HW enable, or both */
 194
 195         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 196         case ACPI_GPE_TYPE_WAKE:
 197
 198                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 199                 break;
 200
 201         case ACPI_GPE_TYPE_WAKE_RUN:
 202
 203                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 204
 205                 /*lint -fallthrough */
 206
 207         case ACPI_GPE_TYPE_RUNTIME:
 208
 209                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
 210
 211                 if (write_to_hardware) {
 212
 213                         /* Clear the GPE (of stale events), then enable it */
 214
 215                         status = acpi_hw_clear_gpe(gpe_event_info);
 216                         if (ACPI_FAILURE(status)) {
 217                                 return_ACPI_STATUS(status);
 218                         }
 219
 220                         /* Enable the requested runtime GPE */
 221
 222                         status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
 223                 }
 224                 break;
 225
 226         default:
 227                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 228         }
 229
 230         return_ACPI_STATUS(AE_OK);
 231 }
 232
 233 /*******************************************************************************
 234  *
 235  * FUNCTION:    acpi_ev_disable_gpe
 236  *
 237  * PARAMETERS:  gpe_event_info          - GPE to disable
 238  *
 239  * RETURN:      Status
 240  *
 241  * DESCRIPTION: Disable a GPE based on the GPE type
 242  *
 243  ******************************************************************************/
 244
 245 acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 246 {
 247         acpi_status status;
 248
 249         ACPI_FUNCTION_TRACE(ev_disable_gpe);
 250
 251         if (!(gpe_event_info->flags & ACPI_GPE_ENABLE_MASK)) {
 252                 return_ACPI_STATUS(AE_OK);
 253         }
 254
 255         /* Make sure HW enable masks are updated */
 256
 257         status =
 258             acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_DISABLE);
 259         if (ACPI_FAILURE(status)) {
 260                 return_ACPI_STATUS(status);
 261         }
 262
 263         /* Mark wake-disabled or HW disable, or both */
 264
 265         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 266         case ACPI_GPE_TYPE_WAKE:
 267                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 268                 break;
 269
 270         case ACPI_GPE_TYPE_WAKE_RUN:
 271                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 272
 273                 /*lint -fallthrough */
 274
 275         case ACPI_GPE_TYPE_RUNTIME:
 276
 277                 /* Disable the requested runtime GPE */
 278
 279                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
 280                 status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
 281                 break;
 282
 283         default:
 284                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 285         }
 286
 287         return_ACPI_STATUS(AE_OK);
 288 }
 289
 290 /*******************************************************************************
 291  *
 292  * FUNCTION:    acpi_ev_get_gpe_event_info
 293  *
 294  * PARAMETERS:  gpe_device          - Device node.  NULL for GPE0/GPE1
 295  *              gpe_number          - Raw GPE number
 296  *
 297  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 298  *
 299  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 300  *              Validates the gpe_block and the gpe_number
 301  *
 302  *              Should be called only when the GPE lists are semaphore locked
 303  *              and not subject to change.
 304  *
 305  ******************************************************************************/
 306
 307 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 308                                                        u32 gpe_number)
 309 {
 310         union acpi_operand_object *obj_desc;
 311         struct acpi_gpe_block_info *gpe_block;
 312         acpi_native_uint i;
 313
 314         ACPI_FUNCTION_ENTRY();
 315
 316         /* A NULL gpe_block means use the FADT-defined GPE block(s) */
 317
 318         if (!gpe_device) {
 319
 320                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 321
 322                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 323                         gpe_block = acpi_gbl_gpe_fadt_blocks[i];
 324                         if (gpe_block) {
 325                                 if ((gpe_number >= gpe_block->block_base_number)
 326                                     && (gpe_number <
 327                                         gpe_block->block_base_number +
 328                                         (gpe_block->register_count * 8))) {
 329                                         return (&gpe_block->
 330                                                 event_info[gpe_number -
 331                                                            gpe_block->
 332                                                            block_base_number]);
 333                                 }
 334                         }
 335                 }
 336
 337                 /* The gpe_number was not in the range of either FADT GPE block */
 338
 339                 return (NULL);
 340         }
 341
 342         /* A Non-NULL gpe_device means this is a GPE Block Device */
 343
 344         obj_desc =
 345             acpi_ns_get_attached_object((struct acpi_namespace_node *)
 346                                         gpe_device);
 347         if (!obj_desc || !obj_desc->device.gpe_block) {
 348                 return (NULL);
 349         }
 350
 351         gpe_block = obj_desc->device.gpe_block;
 352
 353         if ((gpe_number >= gpe_block->block_base_number) &&
 354             (gpe_number <
 355              gpe_block->block_base_number + (gpe_block->register_count * 8))) {
 356                 return (&gpe_block->
 357                         event_info[gpe_number - gpe_block->block_base_number]);
 358         }
 359
 360         return (NULL);
 361 }
 362
 363 /*******************************************************************************
 364  *
 365  * FUNCTION:    acpi_ev_gpe_detect
 366  *
 367  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 368  *                                    Can have multiple GPE blocks attached.
 369  *
 370  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 371  *
 372  * DESCRIPTION: Detect if any GP events have occurred.  This function is
 373  *              executed at interrupt level.
 374  *
 375  ******************************************************************************/
 376
 377 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
 378 {
 379         acpi_status status;
 380         struct acpi_gpe_block_info *gpe_block;
 381         struct acpi_gpe_register_info *gpe_register_info;
 382         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 383         u8 enabled_status_byte;
 384         u32 status_reg;
 385         u32 enable_reg;
 386         acpi_cpu_flags flags;
 387         acpi_native_uint i;
 388         acpi_native_uint j;
 389
 390         ACPI_FUNCTION_NAME(ev_gpe_detect);
 391
 392         /* Check for the case where there are no GPEs */
 393
 394         if (!gpe_xrupt_list) {
 395                 return (int_status);
 396         }
 397
 398         /*
 399          * We need to obtain the GPE lock for both the data structs and registers
 400          * Note: Not necessary to obtain the hardware lock, since the GPE registers
 401          * are owned by the gpe_lock.
 402          */
 403         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 404
 405         /* Examine all GPE blocks attached to this interrupt level */
 406
 407         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 408         while (gpe_block) {
 409                 /*
 410                  * Read all of the 8-bit GPE status and enable registers
 411                  * in this GPE block, saving all of them.
 412                  * Find all currently active GP events.
 413                  */
 414                 for (i = 0; i < gpe_block->register_count; i++) {
 415
 416                         /* Get the next status/enable pair */
 417
 418                         gpe_register_info = &gpe_block->register_info[i];
 419
 420                         /* Read the Status Register */
 421
 422                         status =
 423                             acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
 424                                                    &status_reg,
 425                                                    &gpe_register_info->
 426                                                    status_address);
 427                         if (ACPI_FAILURE(status)) {
 428                                 goto unlock_and_exit;
 429                         }
 430
 431                         /* Read the Enable Register */
 432
 433                         status =
 434                             acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
 435                                                    &enable_reg,
 436                                                    &gpe_register_info->
 437                                                    enable_address);
 438                         if (ACPI_FAILURE(status)) {
 439                                 goto unlock_and_exit;
 440                         }
 441
 442                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 443                                           "Read GPE Register at GPE%X: Status=%02X, Enable=%02X\n",
 444                                           gpe_register_info->base_gpe_number,
 445                                           status_reg, enable_reg));
 446
 447                         /* Check if there is anything active at all in this register */
 448
 449                         enabled_status_byte = (u8) (status_reg & enable_reg);
 450                         if (!enabled_status_byte) {
 451
 452                                 /* No active GPEs in this register, move on */
 453
 454                                 continue;
 455                         }
 456
 457                         /* Now look at the individual GPEs in this byte register */
 458
 459                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 460
 461                                 /* Examine one GPE bit */
 462
 463                                 if (enabled_status_byte & (1 << j)) {
 464                                         /*
 465                                          * Found an active GPE. Dispatch the event to a handler
 466                                          * or method.
 467                                          */
 468                                         int_status |=
 469                                             acpi_ev_gpe_dispatch(&gpe_block->
 470                                                                  event_info[(i *
 471                                                                              ACPI_GPE_REGISTER_WIDTH)
 472                                                                             +
 473                                                                             j],
 474                                                                  (u32) j +
 475                                                                  gpe_register_info->
 476                                                                  base_gpe_number);
 477                                 }
 478                         }
 479                 }
 480
 481                 gpe_block = gpe_block->next;
 482         }
 483
 484       unlock_and_exit:
 485
 486         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 487         return (int_status);
 488 }
 489
 490 /*******************************************************************************
 491  *
 492  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 493  *
 494  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 495  *
 496  * RETURN:      None
 497  *
 498  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 499  *              function is called from an invocation of acpi_os_execute and
 500  *              therefore does NOT execute at interrupt level - so that
 501  *              the control method itself is not executed in the context of
 502  *              an interrupt handler.
 503  *
 504  ******************************************************************************/
 505
 506 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 507 {
 508         struct acpi_gpe_event_info *gpe_event_info = (void *)context;
 509         acpi_status status;
 510         struct acpi_gpe_event_info local_gpe_event_info;
 511         struct acpi_evaluate_info *info;
 512
 513         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 514
 515         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 516         if (ACPI_FAILURE(status)) {
 517                 return_VOID;
 518         }
 519
 520         /* Must revalidate the gpe_number/gpe_block */
 521
 522         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
 523                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 524                 return_VOID;
 525         }
 526
 527         /* Set the GPE flags for return to enabled state */
 528
 529         (void)acpi_ev_enable_gpe(gpe_event_info, FALSE);
 530
 531         /*
 532          * Take a snapshot of the GPE info for this level - we copy the
 533          * info to prevent a race condition with remove_handler/remove_block.
 534          */
 535         ACPI_MEMCPY(&local_gpe_event_info, gpe_event_info,
 536                     sizeof(struct acpi_gpe_event_info));
 537
 538         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 539         if (ACPI_FAILURE(status)) {
 540                 return_VOID;
 541         }
 542
 543         /*
 544          * Must check for control method type dispatch one more
 545          * time to avoid race with ev_gpe_install_handler
 546          */
 547         if ((local_gpe_event_info.flags & ACPI_GPE_DISPATCH_MASK) ==
 548             ACPI_GPE_DISPATCH_METHOD) {
 549
 550                 /* Allocate the evaluation information block */
 551
 552                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 553                 if (!info) {
 554                         status = AE_NO_MEMORY;
 555                 } else {
 556                         /*
 557                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
 558                          * control method that corresponds to this GPE
 559                          */
 560                         info->prefix_node =
 561                             local_gpe_event_info.dispatch.method_node;
 562                         info->parameters =
 563                             ACPI_CAST_PTR(union acpi_operand_object *,
 564                                           gpe_event_info);
 565                         info->parameter_type = ACPI_PARAM_GPE;
 566                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 567
 568                         status = acpi_ns_evaluate(info);
 569                         ACPI_FREE(info);
 570                 }
 571
 572                 if (ACPI_FAILURE(status)) {
 573                         ACPI_EXCEPTION((AE_INFO, status,
 574                                         "while evaluating GPE method [%4.4s]",
 575                                         acpi_ut_get_node_name
 576                                         (local_gpe_event_info.dispatch.
 577                                          method_node)));
 578                 }
 579         }
 580
 581         if ((local_gpe_event_info.flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 582             ACPI_GPE_LEVEL_TRIGGERED) {
 583                 /*
 584                  * GPE is level-triggered, we clear the GPE status bit after
 585                  * handling the event.
 586                  */
 587                 status = acpi_hw_clear_gpe(&local_gpe_event_info);
 588                 if (ACPI_FAILURE(status)) {
 589                         return_VOID;
 590                 }
 591         }
 592
 593         /* Enable this GPE */
 594
 595         (void)acpi_hw_write_gpe_enable_reg(&local_gpe_event_info);
 596         return_VOID;
 597 }
 598
 599 /*******************************************************************************
 600  *
 601  * FUNCTION:    acpi_ev_gpe_dispatch
 602  *
 603  * PARAMETERS:  gpe_event_info  - Info for this GPE
 604  *              gpe_number      - Number relative to the parent GPE block
 605  *
 606  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 607  *
 608  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 609  *              or method (e.g. _Lxx/_Exx) handler.
 610  *
 611  *              This function executes at interrupt level.
 612  *
 613  ******************************************************************************/
 614
 615 u32
 616 acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 617 {
 618         acpi_status status;
 619
 620         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 621
 622         acpi_gpe_count++;
 623
 624         /*
 625          * If edge-triggered, clear the GPE status bit now.  Note that
 626          * level-triggered events are cleared after the GPE is serviced.
 627          */
 628         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 629             ACPI_GPE_EDGE_TRIGGERED) {
 630                 status = acpi_hw_clear_gpe(gpe_event_info);
 631                 if (ACPI_FAILURE(status)) {
 632                         ACPI_EXCEPTION((AE_INFO, status,
 633                                         "Unable to clear GPE[%2X]",
 634                                         gpe_number));
 635                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 636                 }
 637         }
 638
 639         /*
 640          * Dispatch the GPE to either an installed handler, or the control method
 641          * associated with this GPE (_Lxx or _Exx). If a handler exists, we invoke
 642          * it and do not attempt to run the method. If there is neither a handler
 643          * nor a method, we disable this GPE to prevent further such pointless
 644          * events from firing.
 645          */
 646         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 647         case ACPI_GPE_DISPATCH_HANDLER:
 648
 649                 /*
 650                  * Invoke the installed handler (at interrupt level)
 651                  * Ignore return status for now.  TBD: leave GPE disabled on error?
 652                  */
 653                 (void)gpe_event_info->dispatch.handler->address(gpe_event_info->
 654                                                                 dispatch.
 655                                                                 handler->
 656                                                                 context);
 657
 658                 /* It is now safe to clear level-triggered events. */
 659
 660                 if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 661                     ACPI_GPE_LEVEL_TRIGGERED) {
 662                         status = acpi_hw_clear_gpe(gpe_event_info);
 663                         if (ACPI_FAILURE(status)) {
 664                                 ACPI_EXCEPTION((AE_INFO, status,
 665                                                 "Unable to clear GPE[%2X]",
 666                                                 gpe_number));
 667                                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 668                         }
 669                 }
 670                 break;
 671
 672         case ACPI_GPE_DISPATCH_METHOD:
 673
 674                 /*
 675                  * Disable the GPE, so it doesn't keep firing before the method has a
 676                  * chance to run (it runs asynchronously with interrupts enabled).
 677                  */
 678                 status = acpi_ev_disable_gpe(gpe_event_info);
 679                 if (ACPI_FAILURE(status)) {
 680                         ACPI_EXCEPTION((AE_INFO, status,
 681                                         "Unable to disable GPE[%2X]",
 682                                         gpe_number));
 683                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 684                 }
 685
 686                 /*
 687                  * Execute the method associated with the GPE
 688                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 689                  */
 690                 status = acpi_os_execute(OSL_GPE_HANDLER,
 691                                          acpi_ev_asynch_execute_gpe_method,
 692                                          gpe_event_info);
 693                 if (ACPI_FAILURE(status)) {
 694                         ACPI_EXCEPTION((AE_INFO, status,
 695                                         "Unable to queue handler for GPE[%2X] - event disabled",
 696                                         gpe_number));
 697                 }
 698                 break;
 699
 700         default:
 701
 702                 /* No handler or method to run! */
 703
 704                 ACPI_ERROR((AE_INFO,
 705                             "No handler or method for GPE[%2X], disabling event",
 706                             gpe_number));
 707
 708                 /*
 709                  * Disable the GPE. The GPE will remain disabled until the ACPI
 710                  * Core Subsystem is restarted, or a handler is installed.
 711                  */
 712                 status = acpi_ev_disable_gpe(gpe_event_info);
 713                 if (ACPI_FAILURE(status)) {
 714                         ACPI_EXCEPTION((AE_INFO, status,
 715                                         "Unable to disable GPE[%2X]",
 716                                         gpe_number));
 717                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 718                 }
 719                 break;
 720         }
 721
 722         return_UINT32(ACPI_INTERRUPT_HANDLED);
 723 }